1308 Rocer C. Smiru 
at least the prothorax protrude anteriorly and the tail protrudes pos- 
teriorly (fig. 162, page 1366). The larva walks rapidly‘and the packet 
sways from side to side rather unsteadily. 
On removal of the packet it will be observed that the larva possesses 
striking specializations for carrying it. The posterior part is fastened 
to both the lateral and the dorsal abdominal setae. Rows of minute 
setae with recurved tips were discovered on the dorsum of the larvae 
of C. cockerell1, and a later study of preserved material of the other 
trash carriers revealed their presence on these also. In C. cockerelli 
they are more prominent than in the other species, being arranged 
in from one to three rows across the body from the metathorax to the 
seventh abdominal segment inclusive. There are as many as thirty of 
these setae in the longer rows. They are well suited to holding the 
packet materials securely on the abdomen. The anterior half of the 
packet is free, but rests on the up-curved, fan-shaped setae of the 
thoracic tubercles. In addition to the proper support being thus 
given, the free anterior part permits the larva to stretch out in walking 
or running. The tail, being free, is extended and so the larva is unham- 
pered in getting about. The abdominal setae are fairly long and the 
knobs are small. While the abdomen is unusually wide, the segments 
are narrow, so that the abdomen is shorter and more arched than in 
other larvae. 
The building of the packet is most interesting. The performance 
may be observed by taking the packet from a larva in a vial, and 
putting it back into the vial by bits. The larva, with its packet removed, 
runs around rapidly in evident search of something. With its palpi, 
antennae, and jaws it seeks from side to side and in every erevice. Ifa 
fairly large piece of the packet be dropped into the vial, the larva, 
touching it, very quickly crawls under it. As soon as the debris is on 
its back, it is worked backward by the combined efforts of the jaws and a 
shifting of the abdomen. The head can be bent nearly straight back- 
ward when the front pair of legs is lifted, and can be turned to each 
side for a considerable distance. As soon as the large piece of debris 1s 
in place, the larva shifts it from side to side and from the front. A bit 
of the debris is pulled out and poked back into the pack again. In this 
way, the material is made more or less solid and the parts are woven into 
one another to form a firm packet. If more of the debris is added at 
intervals, it is grasped by the larva’s jaws and placed on the anterior 
border of the packet. it is then worked in and pushed backward, and 
the straggling ends are picked up and pushed into the packet. Along 
with the work of the jaws, the abdomen, in a series of wavelike contrac- 
tions, shifts the packet posteriorly. 
